[libvirt] [PATCH 3/4] qemu: fix race between disk mirror fail and cancel

If a VM migration is aborted, a disk mirror may be failed by QEMU before libvirt has a chance to cancel it. The disk->mirrorState remains at _ABORT in this case, and this breaks subsequent mirrorings of that disk. We should instead check the mirrorState directly and transition to _NONE if it is already aborted. Do the check *after* aborting the block job in QEMU to avoid a race. Signed-off-by: Michael Chapman <mike(a)very.puzzling.org&gt; --- src/qemu/qemu_migration.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index 21432c0..39ca37c 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -1852,6 +1852,10 @@ qemuMigrationDriveMirror(virQEMUDriverPtr driver, } else { VIR_WARN("Unable to enter monitor. No block job cancelled"); } + + /* If disk mirror is already aborted, clear the mirror state now */ + if (disk->mirrorState == VIR_DOMAIN_DISK_MIRROR_STATE_ABORT) + disk->mirrorState = VIR_DOMAIN_DISK_MIRROR_STATE_NONE; } if (err) virSetError(err); @@ -1920,6 +1924,10 @@ qemuMigrationCancelDriveMirror(qemuMigrationCookiePtr mig, ret = -1; goto cleanup; } + + /* If disk mirror is already aborted, clear the mirror state now */ + if (disk->mirrorState == VIR_DOMAIN_DISK_MIRROR_STATE_ABORT) + disk->mirrorState = VIR_DOMAIN_DISK_MIRROR_STATE_NONE; } cleanup: -- 2.1.0